Michael Tierra L.Ac., O.M.D., Founder of the American Herbalists Guild
The flowers and bark of the mimosa tree (Albizia julibrissin) are among the most valued of Chinese botanicals for relieving anxiety, stress and depression. Commonly found growing throughout temperate zones in the Western United States albizia is native to China, Persia, Korea and Japan. It is traditionally known as "huan hua" (flowers) and "he huan pi" (bark) and popularly as the "happiness herb," and "collective happiness bark" ,by the Chinese. Recently some Chinese herbalists and acupuncturists have even called it 'herbal Prozac. Its use was first documented in the Shen Nong Ben Cao (Divine Husbandman's Classic of the Materia Medica) during the 2nd century for its mood supportive and calming properties as well as a tonic. , ,  ,) Chinese people traditionally recommend its use for anyone who is suffering from grief as a result of a severe loss.
Both the bark and the flowers of albizia are used as a calming sedative in Oriental traditional medicine. Categorized in the Chinese Materia Medica as a calming spirit herb, the bark is thought to 'anchor' the spirit, while the flowers lighten it. The flowers have also been used for the treatment of insomnia, amnesia, sore throat, and contusion in Oriental traditional medicine (Kang, et al) as well as depression, melancholy and anxiety.
Considering the proliferation of antidepressant drugs throughout the Western world with their increasingly recognized adverse effects, it's wonderful that nature has, in abundance, a safer and better alternative probably growing in close proximity to one's doorstep. In my opinion, albizia offers a more profound effect in treating depression and anxiety than the two most commonly promoted herbs, St Johnswort (Hypericum perforatum) and Kava (Piper methisticum) and thus should be more widely used.
There are broadly three classes of antidepressant medications, Tricyclic Antidepressants (TCA's), Monoamine Oxidase inhibitors (MAOI's) and the most popular, Serotonin Selective uptake inhibitors (SSRI's).
TCA's enhance concentrations of the neurotransmitter chemicals norepinephrine (stimulating) and serotonin (the happiness hormone) in the brain. These are known as monoamines and they must be inactivated and reuptaked by the secreting cells. TRI's block this reuptake, allowing the monoamines to remain active in the body much longer.
MAOI's not only enhance the same neurotransmitters, norepinephrine and serotonin, but dopamine as well (dopamine is the reward, or satisfaction hormone). This is the most dangerous and least prescribed class of antidepressants, because it may also inhibit the reuptake of tyramine, which can cause dangerously acute hypertension.
SSRI's (Selective Serotonin Reuptake Inhibitor's) include the popular drugs Luvox, Paxil, Prozac, Celexa, and Zoloft and work by blocking serotonin reabsorption. Specifically, they prolong the effects of serotonin, with an accompanying sense of prolonged well-being.
All three of these drug catalories list a plethora of possible and, in many cases, likely side effects. These include abnormal weight gain, headache, excessive sweating, upset stomach, diarrhea, sleep disturbances, drowsiness, tremor, weight loss more often than weight gain, and decreased libido. In addition some may predispose one to feelings of apathy, cognitive impairment, sudden irrational bursts of violent rage, and suicide. Expectant mothers generally should avoid their use during the 3rd trimester of pregnancy because of adverse reactions on the infant after birth.
Albizia is thought to enhance all aspects of neurotransmitter secretion and regulation. However, because of its blood-moving properties, it is contraindicated for use during pregnancy.
Increasingly, antidepressants are being prescribed to young children and adolescents. This has been in the news lately because there is evidence that, while externally these drugs may indeed block one's expression of negative thoughts and feelings, for many the emotions become 'stuffed,' resulting in increased thoughts of suicide or sudden outbursts of uncontrollable rage.
Recently and ongoing we have seen the not infrequent reporting in the popular press of the negative effects from increased prescribing of antidepressants to young children and adolescents. This is done mostly for behavioral control, but it may cause irrational outbursts of violent rage and suicidal thoughts. Thus, in some cases the very symptoms these antidepressants are intended to treat can be exacerbated. Antidepressants do not help us work out our problems; they simply alter our response to them. For some this can become like a pressure cooker ready to explode.
With hundred's of years of traditional use, albizia is a terrific antidepressant and anti-anxiety herb with no known side effects. While the traditional Chinese dose is 9 to 15 grams daily, a positive effect can be achieved with as little as 3 grams daily, Therefore, albizia flowers and bark offer an extremely effective and vastly inexpensive alternative to antidepressant pharmaceuticals.
The active constituents of albizia are saponins and tannins, while specifically, it contains albitocin, b-sitosterol, amyrin, 3,4,7-trihydroxyflavone, spinasterylglucoside, machaerinic acid, lactone, methyl ester, acaci acid, and lactone.  Several compounds of flavonol glycosides, which have demonstrated sedative activity , including quercetrin and isoquercetrin are also a part of its constituents. Finally, research has revealed significant antioxidant activity from the bark.
Evidently, few studies of albizia have been conducted. In one animal study examining the sedative effects of a methanol fresh-flower extract (400g in 3 L), two isolated compounds from albizzia, quercetrin and isoquercetrin (flavonol glycosides), were both found to increase pentobarbital-induced sleeping time in a dose-dependent manner in mice. This indicates a possible herb-drug interaction that patients taking sedatives should be made aware of. This substantiates the sedative claims for albizia, as well. Yet, through my experience, and that of my patients, none have ever reported feelings of drowsiness from the recommended or even relatively higher doses of albizia alcoholic extract or powder.
Interestingly, a methanolic extract of the stem bark of Albizia julibrissin was also found to have significant potential in scavenging destructive free radicals, making albizzia a useful anti-aging antioxidant as well. 
In traditional Chinese Medicine, albizzia (bark and flower) is classified as sweet with a neutral energy and enters the heart and liver organ meridians. According to the Chinese Herbal Medicine Materia Medica,  albizia is used primarily for insomnia, poor memory, irritability and angry feelings due to constrained emotions '“ especially when accompanied by epigastric pain and feelings of pressure in the chest. Secondarily, the bark is regarded as one of the most important herbs for the treatment of external trauma and injuries. It promotes blood circulation, reduces pain and swelling, promotes the regeneration of flesh and facilitates the healing of bone fractures.
Those who are presently taking a prescribed antidepressant, and wish to withdraw and possibly substitute albizia flower extract, should consult with their doctor. I have not seen adverse interactions taking both the drug and the herb simultaneously, but I always advise my patients to begin by taking both and then to gradually lower the dose of the drug during the withdrawal period.
Common adulterants found in the market for albizia flowers are certain species of magnolia flowers, which reportedly have similar properties.
A similar yellow flowered species (A. lubek) known as 'shirish' is used as a rasayana or tonic in Ayurvedic medicine for allergic conditions. Indian researchers have been able to substantiate that the antiallergenic properties are due to its ability to prevent mast cell degeneration.
I have given a 5 to 1 alcoholic extract of albizia to many patients for depression, anxiety and insomnia. Usually I prescribe about a half-teaspoon of the extract three times a day and, for more sever cases, up from a teaspoon to a tablespoon three times daily. I also prescribe a 5 to 1 dried powdered extract.
A woman age 54 who had suffered from severe feelings of negativity and depression most of her life, was recommended by a friend, who was already taking antidepressives, to see his psychiatrist. This woman certainly had many reasons for her depression and would benefit from psychotherapy. However, many patients go to a particular psychologist as this woman did, expressly to be evaluated for antidepressant medication.
Unfortunately, like many psychiatrists, this therapist had a reputation for clearing clients, for spending little time with his patients and sending them off with an antidepressant prescription. Case in point, this woman spent a total of seven minutes with the psychiatrist and was sent home with a prescription for one of the Serotonin uptake inhibitor antidepressants. No advice was given as to whether counseling and some lifestyle changes might be a better choice than the drug.
I suggested that she hold off on taking the drug, focus on a few tough decisions and lifestyle changes and that she take a half teaspoon three times daily of a 5:1 extract of Albizia. She reported that after three or four days, she noticed a marked improvement with greater mood stability, and has continued to use the albizzia flower extract rather than use the drug.
Another man, age 43, had a history of episodes of chronic depression, with accompanying morbid thoughts. His wife asked if there was anything I could give him that would help. I gave the same albizia flower extract, but started with a teaspoon of the extract three times daily and after a week, stepping it down to a half teaspoon. He has been on the albizia extract for several months and has reported that while he occasionally has some down moments, they are not nearly as severe as they were previously.
As well as giving albizia to many patients suffering from acute and chronic depression and anxiety I've also given it to those who complain of high stress, with noticed marked improvement '”even after a single day of use. While there are undoubtedly many individuals who will require stronger medication (and for these pharmaceuticals may be of value), albizia is a good choice for probably greater than 50% of those who are presently taking a pharmaceutical drug. At a mere fraction of the price, albizia is devoid of the adverse side effects of the drugs and can be easily stopped at anytime. It seems reasonable to conclude that before one resorts to the use of drugs, that nature's own gift from the 'tree of collective happiness' should be given a try instead.
Caution: Serious chronic depression can be a life compromising and life threatening debility. One should always consult a qualified medical practitioner when attempting to go integrate an herb or any natural approach as an alternative to prescribed medications.
 Kava is suspected of causing liver toxicity among a number of individuals mostly in Germany. Since this report and the subsequent restriction of kava products in many European stores, it was found that to cut costs, certain manufacturers were purchasing the above ground bark for raw material and this is documented in ethnobotanical sources as having potential toxicity that the traditionally used below ground portion of the root bark does not have. Kava is very safe if it is used in its traditional form.
. Chinese Herbal Medicine Materia Medica (revised edition), Bensky, Gamble, & Kaptchuk.
. Chen and Chen, Chinese Medical Herbology, Art of Medicine Press, 2001, pg 768-769
 #1 ibid
 Ikeda, T et al. Cytotoxic Glycosides form Albizia julibrissin, J. Nat. Prod. 1997, 60, 102-107.
 Kang, T.H. et al. Sedative activity of two flavonol glycosides isolated form the flowers of Albiza julibrissin Durazz, Journal of Ethnopharmacology 71 92000) 321-323.
 # 1 and 2, ibid
 Xian Dai Zhong Yao Yao Li Xue (Contemporary Pharmacology of Chinese Herbs), 1997: 1097
 Jung, M.E. et al. Antioxidant activity from the stem bark of Albizia julibrissin, Arch Pharm Res Vol 26, No. 6, 458-462, 2003
 #10 ibid
 . #1 a d 2 ibid